Sodium Cobaltinitrite

The spectrum of sodium cobaltinitrite shown in Fig. 13 is also of type I with the maximum at 27 ev. The spectrum differs from the ammonia and ethylene diamine coordinated cobaltic compounds in yielding a pattern... 

Cobaltinitrite Diammonium sodium cobaltinitrite, (NH4)2NaCo(N02)6H20... 

Cobaltinitrite. Dipotassium sodium cobaltimtnte. K NaCotNO )6"H20, golden yellow precipitate, formed by reaction of sodium cobaltinitrite solution in acetic acid with soluble potassium salt solution Used in the detection of potassium. 

K3 [Co(N02)6] fojrms. This compd is also known as Fischer s Salt or as a pigment Cobalt Yellow. Formation of above complex can serve as the basis of a volumetric detn of Co ion. When a sol K salt is added to sodium cobaltinitrite, Naj [Co(N02)6], a yel cryst ppt potassium-sodium cobaltinitrite K2Na[Co(N02)6], HzO is formed. This com-... 

A. Add a few drops of sodium cobaltinitrite TS to a solution of 0.3 g of sample in 1 mL of glacial acetic acid and 5 mL of water. A yellow precipitate forms. 

Sodium Cobaltinitrite TS Dissolve 10 g of sodium cobalti-nitrite [Na3Co(N02)g] in water to make 50 mL, and filter if necessary. 

Nitro-l,3,4-thiadiazole seems to be the only known representative of this class. It was formed in a Sandmeyer reaction between 1,3,4-thiadiazole diazonium chloride and sodium cobaltinitrite in the presence of copper sulfite. An alleged 2-amino-5-nitro-l,3,4-thiadiazole is discussed in Section IV,B. 

Qualitative tests for thallous compounds are (1) brown precipitate TljS with H2S or (NH4)2S in neutral or slightly acid solutions no precipitate in presence of a strong acid (2) soluble halides produce T1C1, white, TIBr, pale yellow or Til, bright yellow (3) K2CrO< precipitates yellow, TLCrO, (4) PtCh precipitates yellow, TLPtClj (quantitative) (5) sodium cobaltinitrite precipitates thallous salts quantitatively as thallous cobaltinitrite, brilliant red. 

Direct complex and capture agents Cobalt compounds Dicobalt edetate Cobalt histidine Cobalt chloride Cobalt acetate Sodium cobaltinitrite Cobamide Hydroxocobalamin ... 

Another N-donor ligand, which forms extremely. stable complexes, is the N02 ion its best-known complex is the orange sodium cobaltinitrite , Na3[Co(N02)6], aqueous solutions of which were used for the quantitative precipitation of K" " as KaLColNOrls] in classical analysis. Treatment of this with fluorine yields... 

Treatment of sodium cobaltinitrite with methylamine yields the complexes [Co(MeNH2)g (N02)jt]" (x = 4, n = 1 x = 3, n - 0). Methylamine is much more easily displaced than ammonia. ... 

Sodium hexanitritocobaltate(III) (0.167m). Dissolve 6.73g sodium hexanitrito-cobaltate(III) (sodium cobaltinitrite) in 100 ml water. 

Stain Technique No. 1 (Feldspars, Quartz, and Calcite). Chemicals needed in this procedure are concentrated HF (52%), a 5% barium chloride solution in distilled water, a saturated solution of sodium cobaltinitrite, and a solution of amaranth (28 grams of F.D. and C. Red No. 2 pure coal tar dye in 2 liters of water). Amaranth is also called Azorubin S, C. 1.16185, available from Polysciences, Inc., in Warrington, Pennsylvania, and other chemical supply houses. This stain is primarily for silicates, but may include clay minerals when aggregated in shale particles. Testing with the shale, as such, will define the usefulness of the stain in this regard. 

Remove the container with the particles from the acid vapors and, with a small pipette, cover the particles with the sodium cobaltinitrite solution for two (2) minutes. 

Photograph 10-11 Raw feed thin section of 45- to 75-pm material stained with a sodium cobaltinitrite-barium chloride-amaranth solution, revealing potash feldspars (yellow) and calcite (pink to red). (S A6879)... 

Test with sodium cobaltinitrite and silver nitrate ... 

Neutral or slightly acid solutions of potassium salts give a yellow crystalline precipitate with sodium cobaltinitrite, Na8[Co(N02)e] . 

The precipitation of potassium salts by means of sodium cobaltinitrite is appreciably more sensitive if silver salts are present K2Ag[Co(N02)e] is formed in this case. The increase in molecular weight by the substitution of silver for sodium makes the precipitate less soluble than the corresponding sodium compound. Obviously, the test solution must be halide-free. 

Lithium, thallium, and ammonium salts must not be present they also give crystalline precipitates with sodium cobaltinitrite. Ammonium salts... 

Procedure. A drop of the neutral or acetic acid test solution is placed on a black spot plate and treated with a drop of 0.05 % silver nitrate solution and a little solid sodium cobaltinitrite. A precipitate or turbidity indicates the presence of potassium. 

According to Comman, the principal preparation method was by the acidification of solutions of cobalt salts with acetic acid followed by addition of a concentrated potassium nitrite solution. Cobalt yellow would then slowly precipitate as a yellow crystalline mass. The alternative Hayes method involves nitric acid vapours being passed into a solution of cobalt nitrate and potassium hydroxide (or acetate). Finally, a method where solutions of sodium cobaltinitrite and a potassium salt acidified with acetic acid is used was reputedly devised by DeKoninck and published by Adie and Wood (1900 cf. Cornman) as an analytical test but subsequently used to produce pigmentary grades. 

NH4+ also yields a yellow precipitate with sodium cobaltinitrite Na3[Co(N02)6] in neutral medium. The precipitate obeys the formula of a double sodium and ammonium cobaltinitrite (NH4)2Na[Co(N02)6]. (In sodium cobaltinitrite, the ligand N02 is linked by the nitrogen atom. It is an N-donor ligand.)... 

De Mumbrum [1959] has produced a mica-vermiculite conversion by removal of potassium using sodium tetraphenylboron or sodium cobaltinitrite. In the process of conversion, the substance passes through an interstratified stage giving a 12 A reflection. De Mumbrum has also succeeded in partially removing Mg(OH)2 from chlorites by the use of sodium versenate. 

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